Hello, I'm 23 years old and I've been smoking since I was 17, though I quit it a few months ago. I've been spitting some blood with mucus in the mornings for a few years now but mostly I thought that was from the damage heavy smoking gave. like eroding tissues. but since I quit smoking, the amount of blood got more, I've started having some serious heart troubles like fast beating or shortness of breath. I've changed into a healthier way of life, and the coming of the blood stopped for some time. Last night, I lifted a heavy object and had a chest pain, and today I've spit even more amount of blood, my mucus was nearly red. Is that a tumor in a lung cancer?